Re: [Qemu-devel] [PATCH v4 00/10] Consolidate crypto APIs & implementations

[Paolo Bonzini]

On 01/07/2015 19:10, Daniel P. Berrange wrote:
> This small series covers the crypto consolidation patches
> I previously posted:
> 
> RFC: https://lists.nongnu.org/archive/html/qemu-devel/2015-04/msg02038.html
>  v1: https://lists.nongnu.org/archive/html/qemu-devel/2015-05/msg04267.html
>  v2: https://lists.nongnu.org/archive/html/qemu-devel/2015-06/msg00601.html
>  v3: https://lists.nongnu.org/archive/html/qemu-devel/2015-06/msg05059.html
> 
> Currently there are 5 main places in QEMU which use some
> form of cryptographic hash or cipher algorithm. These are
> the quorum block driver (hash), qcow{1,2} block driver (cipher),
> VNC password auth (cipher), VNC websockets (hash) and some
> of the CPU instruction emulation (cipher).
> 
> For ciphers the code is using the in-tree implementations
> of AES and/or the RFB cripple-DES. While there is nothing
> broken about these implementations, it is none the less
> desirable to be able to use the GNUTLS provided impls in
> cases where we are already linking to GNUTLS. This will
> allow QEMU to use FIPS certified implementations, which
> have been well audited, have some protection against
> side-channel leakage and are generally actively maintained
> by people knowledgable about encryption.
> 
> For hash digests the code is already using GNUTLS APIs.
> 
> With the TLS work, and possible future improved block device
> encryption, there will be more general purpose crypto APIs
> needed in QEMU.
> 
> It is undesirable to continue to litter the code with
> countless #ifdef WITH_GNUTLS conditionals, as it makes
> it increasingly hard to understand the code.
> 
> The goal of this series is to thus consolidate all the
> crypto code into a single logical place in QEMU - the
> source in $GIT/crypto and heads in $GIT/include/crypto
> The code in this location will provide QEMU internal
> APIs for hash digests, ciphers, and later TLS and block
> encryption primitives. The implementations will be
> backed by GNUTLS, and either libgcrypt or nettle depending
> on which of these GNUTLS is linking to. In the case where
> GNUTLS is disabled at build time, we'll still keep the
> built-in AES & RFB-cripple-DES implementations available
> so we have no regression vs today's level of support.
> 
> The callers of the crypto code can now be unconditionally
> compiled and, if needed, they can check the availability
> of algorithms they want at runtime and report clear errors
> to the CLI or QMP if not available. This is a minor
> difference in behaviour for the quorum block driver which
> would previously be disabled at compile time if gnutls
> was not available.
> 
> A future posting will include the TLS crypto APIs.
> 
> I have not attempted to convert the CPU emulation code to
> use the new crypto APIs, since that code appears to have
> quite specific need for access to the low level internal
> stages of the AES algorithm. So I've left it using the
> QEMU built-in AES code.
> 
> I've added myself in the MAINTAINERS file for the new
> directories, since it was't clear if anyone else on the
> existing QEMU maintainer list had any interest / knowledge
> in maintaining the crypto related pieces.
> 
> Changes since v3:
> 
>   - Removed need for crypto-internal.h file which was
>     missing from v3 patches sent.
>   - Resolve conflicts with error reporting & main loop
>     API changes / cleanup on master
> 
> Changes since v2:
> 
>   - Remove _(..) gettext markers from error messages
>   - Fix array bounds check in hash module (Richard Henderson)
>   - Fix null dereference in freeing of gcrypt cipher impl
>     (Gonglei)
> 
> Changes since v1:
> 
>   - Add explicit algorithm constants for each AES key size,
>     instead of inferring it from array length
>   - Share code for munging des rfb key bit order
>   - Share code for validating key array size vs algorithm
>   - Refactor built-in cipher impl to reduce number of big
>     switch statements
>   - Fix uninitialized 'Error *err' var
>   - Add comments in places where error reporting should be
> 
> Daniel P. Berrange (10):
>   crypto: introduce new module for computing hash digests
>   crypto: move built-in AES implementation into crypto/
>   crypto: move built-in D3DES implementation into crypto/
>   crypto: introduce generic cipher API & built-in implementation
>   crypto: add a gcrypt cipher implementation
>   crypto: add a nettle cipher implementation
>   block: convert quorum blockdrv to use crypto APIs
>   ui: convert VNC websockets to use crypto APIs
>   block: convert qcow/qcow2 to use generic cipher API
>   ui: convert VNC to use generic cipher API
> 
>  MAINTAINERS                           |   7 +
>  Makefile.objs                         |   1 +
>  block/Makefile.objs                   |   2 +-
>  block/qcow.c                          | 102 ++++++---
>  block/qcow2-cluster.c                 |  46 +++-
>  block/qcow2.c                         |  96 ++++----
>  block/qcow2.h                         |  13 +-
>  block/quorum.c                        |  41 ++--
>  configure                             | 160 +++++++++-----
>  crypto/Makefile.objs                  |   5 +
>  {util => crypto}/aes.c                |   2 +-
>  crypto/cipher-builtin.c               | 398 
> ++++++++++++++++++++++++++++++++++
>  crypto/cipher-gcrypt.c                | 195 +++++++++++++++++
>  crypto/cipher-nettle.c                | 206 ++++++++++++++++++
>  crypto/cipher.c                       |  75 +++++++
>  ui/d3des.c => crypto/desrfb.c         |   2 +-
>  crypto/hash.c                         | 200 +++++++++++++++++
>  crypto/init.c                         | 150 +++++++++++++
>  include/{qemu => crypto}/aes.h        |   0
>  include/crypto/cipher.h               | 210 ++++++++++++++++++
>  ui/d3des.h => include/crypto/desrfb.h |   0
>  include/crypto/hash.h                 | 189 ++++++++++++++++
>  include/crypto/init.h                 |  29 +++
>  target-arm/crypto_helper.c            |   2 +-
>  target-i386/fpu_helper.c              |   1 -
>  target-i386/ops_sse.h                 |   2 +-
>  target-ppc/int_helper.c               |   2 +-
>  tests/.gitignore                      |   2 +
>  tests/Makefile                        |   4 +
>  tests/test-crypto-cipher.c            | 290 +++++++++++++++++++++++++
>  tests/test-crypto-hash.c              | 209 ++++++++++++++++++
>  ui/Makefile.objs                      |   4 +-
>  ui/vnc-ws.c                           |  22 +-
>  ui/vnc-ws.h                           |   2 -
>  ui/vnc.c                              | 119 +++++-----
>  ui/vnc.h                              |   8 -
>  util/Makefile.objs                    |   2 +-
>  vl.c                                  |   7 +
>  38 files changed, 2541 insertions(+), 264 deletions(-)
>  create mode 100644 crypto/Makefile.objs
>  rename {util => crypto}/aes.c (99%)
>  create mode 100644 crypto/cipher-builtin.c
>  create mode 100644 crypto/cipher-gcrypt.c
>  create mode 100644 crypto/cipher-nettle.c
>  create mode 100644 crypto/cipher.c
>  rename ui/d3des.c => crypto/desrfb.c (99%)
>  create mode 100644 crypto/hash.c
>  create mode 100644 crypto/init.c
>  rename include/{qemu => crypto}/aes.h (100%)
>  create mode 100644 include/crypto/cipher.h
>  rename ui/d3des.h => include/crypto/desrfb.h (100%)
>  create mode 100644 include/crypto/hash.h
>  create mode 100644 include/crypto/init.h
>  create mode 100644 tests/test-crypto-cipher.c
>  create mode 100644 tests/test-crypto-hash.c
> 

Since there were no more objections, I'm sending a pull request for this
and assuming that further changes will be handled by you.

Paolo